Transformer and the like



Oct. 12, 1937. J. a. SOLA TRANSFORMER AND THE LIKE F1101 April 17, 19357////////////I///////////A?///////////////I//I/ ii: M a: M i W n 0 5 a 32 W w 7 Q2 LEE Patented Oct. 12, 1937 PATENT OFFICE 2,095,294TRANSFORMER AND THE mm Joseph G. Sola, Oak Park, Ill., assignor to SolaElectric 00., Chicago, 111., a corporation of Delaware Application April17, 1935, Serial No. 16,832

2 Claims.

mounted on iron cores and enclosed within metal casings or locatedadjacent to frames or other parts formed of metal, it has been foundnecessary heretofore to provide insulation in connec tion withall suchcoils carrying high tension currents between the core bars and the innerportions of the coils and between the outer portions of the coils andthe adjacent parts of the core or casing, and the provision of suchinsulation so as to be effective at the required points and themaintainment of such insulation in condition to be effective have beenhighly important factors in the use and operation of transformersrepresenting a substantial portion of the total cost of providing theinstruments and keeping them in condition.

His one of the objects of my invention to provide an improvedarrangement by reason of which the insulation carried by the wire shallprovide the required protection at the inner and outer faces of thecoils without the necessity for the use of any coil insulation whateverat these points in addition to the insulation carried by the wire, andby which the amount of coil insulation necessary to be used at otherpoints is kept to a minimum. To this end, it is one of the objects of myinvention to provide an improved arrangement of windings by which thestructure of the coil itself is utilized for providing efi'ectiveinsulation, utilizing the turns carrying the lower voltage current asinsulation means for the turns carrying the highest voltage current. Itis another object of my invention to provide an improved arrangement inwhich one coil sectionserves as insulationbetween the core or other r,metal parts and another coil section.

It is another object of my invention to provide an improved double coilcomprising two coil sections, one located inside of the other with eachsection wound reversely with respect to the other, with two such doublecoils mounted on the same core bar so as to be influenced -by a singlemagnetic field, and with the outer turns of the outer coil sectionsconnected directly with the inner turns of the inner coil sectionseither by grounding to the core or casing parts or otherwise,

5 whereby the four coil sections are connected in parallel seriesarrangement. By this construction, the high tension turns of each coilsection are located directly adjacent to the high tension turns of theadjacent coil sections, with thepotential of substantially the samevalue in said 5 adjoining turns of the two coil sections, so that thereis no necessity for the provision of any insulation between the sectionsof the double coil arrangement. In this arrangement, no insulation isrequired for the double coils except at the 10 ends where the hightension turns are located close to the core parts.

It is another object of my invention to improve devices of this type insundry details hereinafter pointed out. have accomplished my severalobjects are illustrated in the drawing and are hereinafter specificallydescribed. That which I believe. to be new and desire to cover byLetters Patent is set forth in the claims. 20

In the drawing,

Fig. 1 is a side face view of a transformer, enclosed within a casingwhich is shown in cross section, and with portions of the coils brokenaway for better showing my construction; 5

Fig. 2 is a vertical cross sectional view taken at line 2-2 of Fig. 1;and

Fig. 3 is a diagrammatic view showing the connections of the coilsections.

Referring now to the several figures of the 30 drawing, in whichcorresponding parts are indicated by the same reference characters, l0indicates a laminated core bar having a primary coil II and secondarycoil members [2 and I 3 mounted thereon, a core member ll in the form ofa yoke serving as a return path for the flux established in the core barI 0, the parts l0 and H together constituting a core in the form of aloop. The yoke I4 is provided'with arms l5 and I6 thereon extendingbetween the primary coil ll and the secondary coil members l2 and I3respectively, such arms l5 and I6 extending into close proximity to thecore bar In but stopping short of said bar so as to provide air gaps I1between the arms and the bar In. In the arrangement shown, an insulatingsleeve l8 of any suitable type is provided between the primary coil IIand the core bar 10, and insulation parts I9 in the form of plates arepositioned between the end faces of the primary coil II and the adjacentshunt arms l5 and I6. Rivets 20 are provided in the arrangement shownfor holding the core laminations rigidly together.

As is clearly shown in the drawing, the coil member [2 comprises twocoil sections located The preferred means by which '1 15 one inside ofthe other, the inner coil section being indicated by the referencecharacter 2| and the outer coil section by the reference numeral 22. Inlike manner, the coil member I3 is formed of two sections 23 and 24, onelocated inside of the other. The inner and outer coil sections of. eachof the double coil members l2 and I3 are provided with the same numberof turns, being reversely wound, as is clearly shown in Fig. 3.

In the arrangement shown in Figs. 1 and 2, 'my improved transformer isenclosed within a casing member 25 comprising a lid or cover portion 26,the walls of the casing being located in close proirimity to the coremeans and to the outside face portions of the coil sections 22 and 24.The casing member 25 is provided in its ends with outlet bushings 21 ofany suitable type for carrying the high tension wires out of the casing.

In the arrangement shown, the outside turns of the outer coil sections22 and 24 are grounded to the cover plate 26 at the points 28 and29'respectively. The inside turns of the inner coil sections 2| and 23are grounded upon the core bar III at the'points 30 and 3| respectively.A circuit lead 32' is connected with the inside turns of the outer coilsection 22 and with the outside -turns of the inner coil section 2|, anda circuitlead 33 is connected with the inside turns of. the, outer coilsection 24 and with the outside turns of the inner coil section '23.

coil sectionsof each double coil connected in parallel arrangement withrespect to each other.

As will be readilyunderstood, the coil sections The coil sections-2| and24 are connected and wound so as to cooperate, and the .coil sections 22and 23 are likewise connected and wound for cooperative results.

The resistance of the coil sections 24 and 2| is equal to the resistanceof the coil sections 23 and 22, with the result that thefour coilsections operate in complete equilibrium.

By reason of my improved arrangement of the coils, the outside turns ofthe outer coil sections and the inside turns of the inner coil sectionsall have substantially zero potential so' as to make it unnecessary toprovide any insulation between such turns and the adjacent metal parts.The inner and outer coil sections of each of the double coils are woundand connected so as to cooperate with each other forthe production ofinduced current, the outside turns of the inner 7 complete protection ofthe secondary coils.

By my improved construction, in which the induced current is carried bytwo coil structures connected in parallel, wire of just half the sizenecessary for a single coil arrangement is of course used for suchcoils, this being effected without any change in the resistance featureof the transformer. Inasmuch as the windings are arranged in foursections in lieu of the usual two By this means, the f coil sections ofthe two double coils are connected in series between the leads 32 and33, with the' sections or coils, it willbe appreciated that the repairof. a transformer in which there has been a short circuit may sometimesbe effected much more readily by reason of my'improved construction.

By the use of my construction, a transformer properly insulated can beproduced. at a very out heretofore in connection with the secondarycoils. Such p1ates'34 may moreover be of sucha character as to. beeffective for many years without deterioration even when the transformeris substantially overloaded so as to cause heating such as would veryquickly break down many types of. insulation as heretofore employed.

While I prefer to employ the form of device as shown in my drawing andas above described, it is to be understood that my invention is notlimited to such features except so far as the claims may be so limitedby-the prior art;

I claim:-

'1. In a device of the type described, the combination. of a core in theform of a loop, primary coil means on said core for magnetizing it, two

secondary coil sections on said core loop in spaced relation to saidprimary coil means and eachcomprising a plurality of layers of turns,with the inside turns of said secondary coil sections connectedtogether, and arranged so that said secondary coil sections cooperatewith each otherwith respect to the production of an induced current, twoother secondary coil sections mounted on said first named secondary coilsections respectively and each comprising a plurality of layers ofturns, with the outside, turns of said second named secondary coilsections connected together and the inside terminals of said secondnamed secondary coil sections joined with the outside terminals of saidrespective first named secondary coil sections, and with said secondnamed secondary coil sections arranged so that they cooperate with eachother and cooperate with said first named secondary coil sections withrespect to the production of an induced current, output leads extendingfrom said joined terminals respectively, shunt core means providing amagnetic return path including an air gap effective between said primarycoil means and two (if said secondary coil sections, and other shuntcore means providing a magnetic return path including an air gapeffective between said primary coil means and the other twosecondarycoil sections.-

2.\In a device of the type described, the combination of a core bar,primary coil means mounted on said-core bar for magnetizing it, twosecondary coil sections mounted on said core bar on opposite sides ofsaid primary coil and, in spaced relation'thereto and each comprising aplurality of layers of turns, with the inside turns of said the outsideterminals. of said respective first.

named secondary coil sections, and with said second named secondary coilsections arranged so that they cooperate with each other and cooperatewith said first named secondary coil sections with respect to theproduction of an induced current, output leads extending from saidjoined terminals respectively, each of said four secondary coil sectionshaving approximately the same number of turns therein, auxiliary coremeans con- 1 necting the ends of said core bar about all of said coilsprovldinga return path for the magnetic flux set up in said core bar,shunt core means providing a magnetic return path including, an air gapeifective between said primary coil means and two of said secondary coilsections, and other shunt core means providing a magnetic return pathincluding an air gap eflective between said primary coil means and theother two secondary coil sections.

JOSEPH G. SOLA.

